Dispersion (surface chemistry)

The dispersion D in surface chemistry is defined as

${\displaystyle D={\frac {N_{\text{Oberfläche}}}{N_{\text{gesamt}}}}}$

with : number of atoms on the surface and : total number (bulk) of atoms in the solid / nanoparticle / cluster ${\displaystyle N_{\text{Oberfläche}}}$ ${\displaystyle N_{\text{gesamt}}}$

The dispersion is the ratio of surface atoms to total atoms of a solid or nanoparticle. With the closest packing of atoms, the dispersion decreases with the number of atoms.

example

For a cluster that consists of four tetrahedrally arranged spherical atoms, for example, D = 100%, because here each atom is a surface atom.

Dispersion when adsorbed on surfaces

In adsorption processes , the dispersion of surfaces depends on the strength of the interaction of the adsorbate with the surface.

• Low dispersion occurs when the interactions between the adsorbed particles are stronger than with the surface.
• High dispersion occurs when the adsorbed particles interact more strongly with the surface than with their peers.